Often an individual desires a light source to illuminate an area while performing a task or a light source directed in a general outward direction for visibility. Holding a flashlight is an option, but such lighting devices are often cumbersome and may detract from the task being completed because the flashlight must be held. As a result, hands-free lighting is often used because the individual desiring illumination does not need to hold the light source. Common types of hand-free lighting include light sources mounted to headgear or eyeglasses.
Light sources on eyeglasses usually include mounting arrangements of the light source, which may be an LED, on either the cross-frame or temple of the eyeglass so as to provide illumination forwardly of the wearer. In such configuration, lighted eyeglasses are typically used to provide directed or focused light so that an area immediately forward of the wearer, e.g., 6-24 inches from their eyes, can be illuminated for tasks such as reading typical sized print. For other activities, such as walking at night, camping or emergency use, lighting areas even further ahead of the individual may be desirable. However, prior lighted glasses configured to provide hands-free lighting for some of these various purposes have often been heavy, bulky, inconvenient, and/or otherwise provide unsatisfactory performance.
Some prior lighted glasses have separate and bulky lighting modules fastened to the glasses such as disclosed in U.S. Pat. Nos. 5,541,767 to Murphy et al.; 4,959,760 to Wu; and 3,769,663 to Perl. Because of their large lighting modules, these glasses are bulky and may be fairly heavy making them inconvenient for a user to wear. Further, these prior lighted glasses conspicuously mount the lighting modules to the glasses or incorporate electronic components for the lighting therein so that the presence of the light modules or electronic components is visually prominent when the glasses are worn, giving the glasses an unsightly appearance.
Prior lighted glasses are also known where lighting components including the light and power sources and the light switch are distributed along the eyeglass frame by mounting the light source to the front cross-frame member of the glasses and then mounting the other electrical components for the light source to the temple arms. In one arrangement, wires of the electrical components are run from the power source to the light source across the pivot connections between the temple arms and the front cross-frame member, such as disclosed in U.S. Pat. Nos. 5,946,071 to Feldman and 5,722,762 to Soll. These glasses, however, can complicate the pivoting action between the temple arms and the front frame member due to the wires spanning the pivot connection between the temple arms and front, cross-frame member of the glasses. If the wires are run outside of the frame of the glasses, the glasses are provided with an unsightly appearance.
Lighted glasses are known that utilize the pivoting motion of the temple arms to turn the lights on and off so that the glasses have hinge switches, such as those as disclosed in U.S. Pat. Nos. 5,218,385 to Lii; and 4,283,127 to Rosenwinkel; and U.S. Patent Publication Nos. 2003/0189824 to Meeder et al. and 2006/0012974 to Su. The hinge switch powers the light source when the temple arms are unfolded and turns off the light source when the temple arms are folded. Typically, the hinge switch employs separate electrical contacts on the temple arm and the cross-frame member so that when the temple arms are unfolded, the contacts engage each other to provide power to the light source. In this manner, use of wires spanning the pivot connections between the temple arms and cross-frame member is avoided. However, the use of moving parts to establish an electrical connection between a power source mounted to the temple arms and a light source mounted to the cross-frame member creates reliability problems. For instance, with repeated usage and pivoting of the temple arms relative to the front cross-frame member, the tolerances therebetween can change so that the degree of engagement between the contacts changes which can cause intermittent conductance between the contacts when the temple arm members are pivoted open. Such intermittent conductance results in the lights blinking on and off. Similarly, repeated usage can cause wear of the engagement surfaces of the contacts also resulting in the blinking problem created by intermittent conductance across the contacts. In addition, if the glasses only use a hinge switch, the lights are always on when the temple arms are pivoted open and thus cannot be used as conventional, unlighted glasses. One solution is to provide another on/off switch, but this undesirably adds complexity and cost to the lighted glasses and requires additional electronics on the glasses which can contribute to an unsightly appearance.